Definition

Obsessive-compulsive disorder (OCD) is a type of anxiety disorder. A person with an anxiety disorder worries excessively about the circumstances of his or her life over a long period of time. OCD is characterized by distressing thoughts that never seem to go away. These thoughts are often accompanied by images that are powerful, unusual, frightening, or absurd.

A person with OCD deals with these thoughts and feelings with ritualized actions. A ritualized action is a behavior that is performed again and again in exactly the same way. Patients believe that these actions will protect them from the terrible thoughts in their minds. Ritualized actions are often unusual and meaningless. They are also called compulsions or compulsive behaviors.

OCD is sometimes known as the "disease of doubt." The patient often knows that his or her obsessive thoughts and ritualized actions are not rational (make no logical...